Does The Earth Receive Heat From The Sun?

The following explanations have been offered , to account for the loss of heat in elevated positions , by those persons who advocate the theory that heat emanates from the sun : — 1 st . That the earth is heated by the

sun ' s rays , but as those rays are constantly radiating from the surface , a large proportion is lost by ascending to great elevations .

2 nd . That the heat rays ol the sun which fall upon the earth , are reflected into the air , and to a great extent lost at great heights . 3 rd . That the highest elevation ever attained is too insignificant to be considered any nearer the sun , when compared with its immense distance .

In reply to the first statement : If the earth is heated by the rays of the sun , it must necessarily absorb them ; and if it does absorb them , then it cannot possibly radiate them at the same time . If a hot cannon ball be placed in a vessel containing cold water , the ball will radiate heat into the water until the ball and the

water become the same temperature . If , on the other hand , a cold ball be placed in hot water , then the water will radiate heat , which the ball will absorb , but the ball cannot absorb heat from , and radiate heat into , the water at one and the same time ; neither

can the earth act in like manner with regard to the sun . Radiation implies cooling , and that part of the earth which is fully exposed to the ( heat ) rays of the sun , cannot bo cooling , else when is it heated ? The operations of radiation appear to be as

follow—There is a large amount of heat generated in the atmosphere during the day , which the earth absorbs—just like the cannon ball before mentioned—but after the sun has set , then the earth gives out or radiates its redundant heat into the atmosphere ( which is then in a quiescent state

, and no longer generating heat ) , and thus by the heat being alternately absorbed by the atmosphere and then by the earth , there is no loss , and the fearful extremes of heat and cold which would otherwise

ensue are prevented . In reply to the second statement : The heat is supposed to be lost by reflection , This seems to me very unlikely , and

contrary to all experience and evidence . If the sun ' s rays travel over ninety millions of miles before they reach the earth , surely they are not utterly annihilated by _ being reflected ten or even 100 miles in the opposite direction . An illustration of such

a phenomenon would be to imagine a thermometer in contact with a brick wall , with a huge fire ninety feet distant , so large and fierce that the thermometer rises to 100 degrees , then upon its being removed one ten-thousandth part of an inch nearer

the fire , it sinks to zero by the loss of reflected heat from the wall . This , as before stated , is contrary to all evidence . In reply to the third statement : I agree that the highest elevation attained is inconsiderable when compared with the sun ' s

distance , and , therefore , more heat on that account can scarcely be expected ; but it must be borne in mind , the heat is actually less , and if we take into consideration ¦ the total heig ht of the atmosphere , and its diminished density as we ascend , then five or six miles is not such an insignificant proportion , but corresponds with the diminished temperature .

IT is possible that the foregoing may , after all , be considered only a mere quibble of words , without any material significance , even if true , and certainly not worth the endeavour to oppose the long established belief that heat emanates from the sun .

This , however , is not the case , the great object being to state the literal truth ; besides which , if heat is generated in the atmosphere , several phenomena , otherwise most perplexing and unaccountable , are easily understoodwhich gives the

ques-, tion greater importance . 1 st . If the sun gives out such immense heat as attributed to it , how is the supply restored 1 Do millions of meteors and comets fall into it daily to keep up the conflagrationas some writers suggestor is

, , it cooling down ? And if so , why is it not already utterly consumed ? for it has been estimated that its whole bulk should not last more than 5 , 000 years . The very persons who make these calculations tell us that heat is motionnot matter .

, This theoretical puzzle is answered if heat is generated in the atmosphere , for then it is clear the sun loses nothing , and , therefore , requires no replenishing .